Silver Spring Transit Center Offers Lessons for Purple Line

Sometime in the next two weeks, Maryland Transportation Secretary Pete Rahn is expected to announce his decision on whether the state will to move ahead with the Purple Line. Before that, Prince George’s and Montgomery County Executives are meeting with Rahn to make their final pitch in support of the project.

One of that meeting’s topics ought to be Montgomery County’s Silver Spring Transit Center. Once supposed to open in 2009 at a cost of $30 million, costs have ballooned to over $140 million. It remains closed because of safety concerns due to structural and design problems. Over two decades after the county first bought the land and more than eight years after construction began, the Silver Spring Transit Center remains empty and unused behind a chain-link fence.

Excellent reporting by Washington Post‘s Bill Turque has shed considerable light on the underlying problem, the initial project requirements and design. The project’s original design was flawed because it failed to require the necessary extra support, referred to as “post-tensioning in the pour strips.”[1]

So what transportation design firm was responsible for the Silver Spring Transit Center’s flawed design, especially the failure to require the necessary extra support? Parsons Brinckerhoff.

And what engineering firm did the state contract with to furnish for ridership and other financial projections being used to justify the construction of Purple Line? Parsons Brinckerhoff.

Earlier this year, the state’s Office of Legislative Audits found that Maryland Transit Administration had failed to verify the accuracy of millions of dollars in contractor-submitted architectural and engineering costs for the Red and Purple light rail lines. And which company is a lead part of a joint venture team handling both engineering for the Red Line and program management for the Purple Line? Parsons Brinckerhoff.

The Purple Line’s proponents’ very rosy estimates of 69,000 daily trips deserve considerable scrutiny. Transit ridership is a function of population and job densities. New Jersey’s Hudson-Bergen light rail, for example, serves an area that has four times the population density of the Purple Line and a job center with 123,000 jobs, far more than any point on the Purple Line. Yet the Hudson-Bergen line carries only 44,000 trips a day.

Even at the 69,000 traffic projections, the overwhelming majority of projected Purple Line riders already use other mass transit. In fact, given light rail’s slow speed and uncertain fare box requirements, existing transit connections may remain the preferable alternative for transit riders. Should the ridership projections fall short, billions could be spent without any increase of mass transit ridership.

So when County Executive Ike Leggett meets Maryland Transportation Secretary Rahn, one question worth asking is, “County Executive, based on your past experience with Parsons Brinckerhoff, just how much confident should we be in their Purple Line projections?”